CVE-2026-85863: CWE-416: Use After Free in Microsoft Windows 10 Version 1607

CVE-2026-85863 is a use-after-free vulnerability (CWE-416) in the Windows Clipboard User Service component of Microsoft Windows 10 Version 1607 and subsequent builds. An authorized attacker with local access can exploit this flaw to elevate privileges on the affected system. The vulnerability affects multiple Windows 10 build ranges starting from 10.0.14393.0 up to but not including various patched builds (e.g., <10.0.14393.9612, <10.0.17763.9376, etc.). The CVSS v3.1 base score is 7.8, indicating high severity, with attack vector local, high attack complexity, low privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.

Successful exploitation allows a local authorized attacker to elevate privileges, potentially gaining higher system rights than intended. This could lead to full system compromise depending on the privileges escalated. The vulnerability affects confidentiality, integrity, and availability of the system.

An official fix from Microsoft is available and should be applied promptly. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85863 for update details and installation instructions. No additional mitigations are specified beyond applying the official patch.